Hoisting apparatus.



PATENTED AUG. 13, 1907.

D. 0'. PRITGHARD. HOISTING APPARATUS. APPLICATION rum) JULY 7, 190g.

INVENTOR Zcfiard 1 C 0 3 121 n o ,w a w w I o a L/ j 6 you? mw La ATTORNEY.

' WITNESSES: I

DAVID O. PRITOHARD, 'OF CARDIFF, MARYLAND.

HOIS'IING APPARATUS.

Specification of Letters Patent.

Patented Aug. 13, 1907.

Application filed July 7,1906. Serial No. 325,057.

To all whom it may concern:

Be it known that I, DAVID O. PRITCHARD, a citizen of the United States, residing at Cardiff, county of Harford, and State of Maryland, have invented a certain new and useful Improvement in Hoisting Apparatus, of which the following is a specification.

My invention relates to a new and useful improvement in hoisting apparatus, and has for its object to provide a simple and effective construction by which a conveyer when loaded may be elevated and transferred to any desired point and then automatically dumped and returned to the point of excavation, the process being repeated indefinitely.

With these ends in view, this invention consists in the details of construction and combination of elements hereinafter set forth and then specifically designated by the claims.

In order that those skilled in the art to which this invention appertains may understand how to make and use the same, I will describe its construction in detail, referring by letter to the accompanying drawing forming a part of this specification, in which- Figure 1 is an elevation of my improved apparatus showing the position of the mechanism just prior to it being brought into position for dumping the conveyer. Fig. 2. a similar view showing the mechanism after it has been brought into position to dump the conveyer. Fig. 3, is an end elevation taken at right angles to Fig. 1. Fig. 4, is an end elevation taken at right angles to Fig. 2.

In carrying out my invention as here embodied, A represents a truck, the grooved wheels B of which are adapted to run upon the cable 0, and from this truck depends the frame work D which may be of any suitable design or construction to suit the requirements of the apparatus.

Within the depending frame is journaled the pulleys E and E, over which the hoisting rope F runs, the latter passing around the pulley G, which latter is journaled in the shive G and terminating in the hook H by means of which the hoisting rope is attached to the conveyer I.

.T represents a lever which is pivoted at K to the frame, a portion of which is curved and adapted to be actuated by the shive G when the latter is raised to a certain height, and this lever has passing through its outer end which is slotted for that purpose the curved lever L, which latter is also pivoted to the frame, the function of which will hereinafter be explained.

M is a latch pivoted to the frame at M and having pivoted to its heel end the spring actuated link N, from which projects the pin N with which the spring actuated pawl O is adapted to engage, and this link passes through a suitable guide P so as to keep it in its proper relative position to the pawl while allowing it a limited swinging movement.

The pawl O is connected with the lever J by the link Q, the lower end of this last named link being slotted so as to permit the lever .I to move upward without effecting the movement of the pawl 0 but permitting the downward movement of the lever .I to draw the pawl O downward.

R represents a chain, the lower end of which is attached to the conveyer I while its upper end is attached to a short rod S having the cross-pin T projecting therefrom, and this short rod passes through the arm G formed with the shive G.

From the foregoing description the operation of my improvement will be obviously as follows: The con veyer is drawn over any point from which material is to be excavated by the proper operation of an endless rope or cable U attached to the frame when the hoisting rope is run out so as to lower the conveyer within easy access of the workmen, and after this conveyer has been loaded the hoisting rope is drawn in thus elevat ing the conveyer until the shive G strikes against the curved portion of the lever J lifting it from the position shown in Fig. 1 to the position shown in Fig. 2, during which movement of this lever the lever L will be swung inward beneath the cross-pin T and the lever I will be locked by the engagement of the latch M with the pin .I from the outer end of this lever, and so long as the lever .I is held in its elevated position the lever L will also be held beneath the cross-pin T by reason of the vertical portion of said lever L, bearing against the rear wall of the slot through which it passes in the lever I. The upward movement of the lever J also carries the pawl 0 into the field of movement of the pin N on the link N, but said pin will not be engaged by said pawl until the link N has been moved forward as hereafter explained. Now by lowering the conveyer the chain R will be retained against down ward movement by the cross-pin 'I resting upon the curved lever L, thus holding the rear side of the conveyer against downward movement while the front end thereof will be lowered, upsetting the conveyer and dumping its load therefrom. To release the chain so as to permit it to again move downward that the conveyer have a new load, the shive is again elevated to a slightly greater distance than upon the previously upward movement and thus carries the lever .T to a higher point, and this ultimate upward movement of the lever .I causes the pin J to ride against the swelled portion M of the latch M forcing the nose of this latch out of the line of travel of the pin J, by which movement of the latch the pin i carried by the link N will be brought into engagement with the pawl 0 where it will be retained until the shive has been lowered sufliciently to imlatch the pawl 0 through the downward movement of the link Q, and before this has taken place the pin .I carried by the lever J will have passed below the nose of the latch thus permitting lever .I

to continue in its downward movement to the position shown in Fig. 1 thereby freeing the lever L from the cross-pin 'l and permitting the chain to travel downward with the shive and conveyer, and after the conveyer has received a new load the above described operation is repeated, it being understood that when the conveyor has been elevated to the point shown in Fig. 2 it may then be moved lengthwise of the cable C to any desired point for dumping, and after being dumped again returned to the proper point for a new load.

By the use of my improvement material may be elevated and conveyed to any point and then dumped entirely under the control of the engineer or attendant upon the motor without the necessity of a separate attendant, for either dumping the conveyor or resetting it fona new load, thus saving considerable time and expense in such operations.

In the old type of self dumping apparatus there are two stationary hooks corresponding to L in the drawing, and when the apparatus is run out to the place of dumping it must be stopped suddenly in order to make the conveyer swing back and forth and at the proper time. It the engineer is an expert he can dump the conveyor, but this is time lost and can be overcome by my invention.

Sometimes there is a heavy fog in the morning and the man in charge cannot see out as far as the place of dumping and it is all guess work with the old style apparatus, sometimes it will dump and sometimes not. It often happens that the conveyor is brought back over the quarry still loaded having failed to dump the load, but with my invention this will be overcome as the apparatus is set to dump before it leaves the place of excavation.

Having thus fully described my invention, what I claim as new and useful, is

1. 111 a hoisting apparatus, a truck, a frame work depending from said truck, a shive, a hoisting rope for raising and lowering said shive, a conveyor supported by said shive, a chain attached to the conveyer and loosely supported by the shive, a lever adapted to be swung upward by the shive, a second lever actuated by the first named lever and adapted to pass into engagement with said chain, means for locking the first named lever in its elevated position whereby the second named lever will be held in engagement with said chain, means for unlocking said first named lever by a final upward movement of the latter and means for restoring the locking mechanism to its normal position by the downward movement of the said first named lever, as specified.

:2. In a hoisting apparatus, a truck, a frame work depending from said truck, a shive, a hoisting rope for raising and lowering said shive, a conveyor suppported by said shive, a chain attached to the conveyer and loosely supported by the shive, a lever adapted to be swung upward by the shive, a second lever actuated by the first named lever and adapted to pass into engagement with said chain, alatch adapted to engage the first named lever and lock the same in its elevated position whereby the second named lever will be held in engagement with the chain upon the next downward movement of the shive to effect the dumping of the conveyer, means for swinging the nose of the latch out of the line of travel of the first named lever, locking mechanism connected with the latch and the last named lever whereby the nose of said latch will he held out of the line of travel of the first named lever until the latter has passed below said latch'and for unlocking the latch after the first named lever has passed below the latch, as and for the purpose set forth.

3. In a hoisting apparatus, a truck, a frame work depending from said truck, a shive, a hoisting rope for raising and lowering said shive, a conveyor supported by said shive, a chain attached to the conveyor and loosely supported by the shive, a lever adapted to be swung upward by the shive, a second lever actuated by the first named lever and adapted to pass into engagement with said chain, a latch adapted to lock the first named lever in an elevated position, a swell formed upon said latch with which the first named lever is adapted to engage for unlocking the latch, a link pivoted to the latch, a pawl adapted to engage with said link when the latch is swung out of its locking position, a link connecting the pawl with the first named lever whereby the complete downward movement of said lever will disengage said pawl from the first named link and permit the latch to be restored to its normal position, as and for the purpose set forth.

-l. The herein described combination of a truck adapted to travel upon the cable, a frame work depending from said truck, a rope for moving the truck along the cable, a hoisting rope passing over pulleys journaled in the frame, a shive carrying a pawl around which the hoisting rope passes, a conveyer supported by the shive, a chain attached to the conveyor, a rod to which the upper end of the chain is attached, an arm carried by the shive through which said rod passes, a cross-pin secured to the upper end of the rod and by which said rod is supported upon the arm, a lever J pivoted to the frame, a lever L engaging with the outer end of the lever J so as to be actuated thereby and brought beneath the cross-pin when the lever .l is elevated, a pin J carried by the end of the lever .l, a latch having a nose and a swelled portion M both of which are adapted to be engaged by said pin J, a link N pivoted to the heel of the latch, a pin N carried by the outer end of the link N, a spring actuated pawl 0 adapted to engage the last named pin when the mechanism is in a certain position and a link Q connecting the pawl O with the lever J, all arranged substantially as and for the purpose set forth.

in testimony whereof, I have hereunto afiixed my nature in the presence of two subscribing witnesses.

DAVID O. IRl'lCI'IARD.

Witnesses l Ross Scannononorr, ll. 0. lnr'rcimnn. 

